Even if it was fully green, you can’t run an electrolysis system from home. So you have to buy it, so there’s a market and an expensive solution.

Electricity comes out the wall.

> Electricity comes out the wall.

Which unless you have solar, you are paying for. Even if you have solar, you are paying off the panels, batteries and inverter/chargers over a period of time.

Nothing is free.

What do you mean?

You can run electrolysis from a cup.

I know, I have one of those weird H shaped flasks with the plat electrodes.

I also have a gas bbq, yet couldn't fill up a LNG car at my house. Maybe there's something more to it than just making small amounts of room temperature / pressure H2.

You can’t make and store bulk hydrogen at home

You can’t.

I’m willing to give it a go.

I’ve got the excess solar from the rooftop solar panels, the electrical and electronic knowledge, and the gas fitter and metal fabrication experience.

I have an oil free air compressor, and anyone can by a helium based cryo-cooler. I have an account with an industrial gas supplier.

Just enough knowledge to be dangerous.

If Nile Red hasn’t blown his lab up by the time I publish this comment, I reckon I stand a chance.

Round trip efficiency of hydrogen is at best 50% and at worse half that. You have the horrendous efficiency of electrolysis and then the equally bad efficiency in the fuel cell.

Efficiency pumping your excess solar into the EV itself is more like 80-85%, most of which is loss in the electronics, not the battery - those typically have a coulombic efficiency of over 95%.

Hydrogen a boondoggle. It's not nearly as stupid as making ethanol from corn (which is an energy-negative process) but it's close.

Also, "gas fitter and metal fabrication" experience isn't worth anything unless it was hydrogen-specific. It is far leakier than natural gas/propane. One of the biggest hassles of a hydrogen fuel chain is that the stuff leaks through everything.

> Round trip efficiency of hydrogen is at best 50%

In fact, even this level of efficiency may be sufficient. Solar panels are so cheap that if we had affordable, long-term energy storage options, even with such efficiency, we would have completely abandoned fossil fuels. But, unfortunately, storing hydrogen is difficult and dangerous. It is not like natural gas.

> It's not nearly as stupid as making ethanol from corn (which is an energy-negative process) but it's close.

Ethanol is produced from corn not for energy purposes, but for food security. It's like a placeholder for real corn so that if there's a crop failure for a couple of years, the low-iq idiots who think it's stupid to make ethanol from corn don't starve to death.

Well... How successful is the US in cutting ethanol consumption on the years the corn production is lower?

Meat usually does that stabilizing. Fuel consumption not even is almost completely inelastic, but corn ethanol on the US is subsidized on every stage to the point that market forces become meaningless.

> Ethanol is produced from corn not for energy purposes, but for food security

Source? First time I read this, might make sense. Although I don't see how this corn should be unaffected by crop failure if all other corn harvests failed.

> Although I don't see how this corn should be unaffected by crop failure if all other corn harvests failed.

I believe the argument being made here is "we need to overproduce corn in order to get food security; what can we do with the spare capacity in the good years given we're already eating too much?"

I don't know if this argument is correct, but I believe that's what's being claimed.

> Ethanol is produced from corn not for energy purposes, but for food security.

No, it's done to subsidize (bribe) farmers. Food security is merely the excuse used to sell it to the non-farmer voters.

Yes, this is literally bribing farmers (extremely cheaply) so that in the event of a prolonged crop failure they will have more arable land and equipment to cultivate it and compensate for the crop failure.

Your air compressor would get you about 2% of the way to where you need to be whilst also turning any your garage into a bomb.

If you had the knowledge necessary to do this, I would assume that would’ve surfaced reasonably early in the thought process.

No air compressor can compress hydrogen, nowhere near the necessary tip velocity.

I hope you’re not my neighbor.